The JSON format is an open standard format. The format of data looks very easy to understand and the data objects consist of attribute-value pairs.

 
ContentEncoding: It helps to indicate the content encoding type, the default encoding for JSON is UTF-8.
ContentType: It helps to indicate the content type. The default content type for JSON is application/json; charset=utf-8.
Note: ContentType and ContentEncoding are not necessary to mention when sending the data in JSON format as the HTTP headers are having a responsibility to tell the recipient what kind of content they're dealing with.
Data: This indicates what the content data is, that means what you will send in JSON format.
JsonRequestBehavior: This property has two options. Those are AllowGet and DenyGet. The default option is DenyGet. When you send data in JSON format, using Get Request, it's necessary to specify the property as AllowGet otherwise it shows the error as “The request would be blocked since the JSON data is considered as sensitive data information”.
MaxJsonLength: This helps to get or set the maximum JSON content length that you will send. The default value for this is 2097152 characters, that is equal to 4 MB of Unicode string data. You can even increase the size based if needed, for that you will get an idea later in this article.
RecursionLimit: Indicates the constraining number of object levels to process. The default value is 100. It means you can serialize the objects that are nested to a depth of 100 objects referencing each other. In a general scenario, the default limit 100 is obviously sufficient when you deal with a JsonResult so there is no need to increase it even though you have the option to increase the limit if required.

Sample Project with Various Scenarios by using JsonResult
Create a new project with the name JsonResultDemo and choose the template as MVC as shown in the following screenshots.

Now, click on the OK button then the displayed screen is as in the following.

As in the preceding template, you need to select the “Add Unit Tests” option as well. So It helps to create a Unit Test project and then again click on the OK button then the project will be created and the startup application page displayed like the following.

Now, add a controller and provide the name as “JsonDemoController” as in the following.

Click on the Controller and then it will open the popup window as in the following.

Now, click on the “Add” button and then it opens a popup to enter the name. So enter the name as “JsonDemoController” as shown in the screenshot.

After adding the controller to the project the controller page looks like the following.

Until now, you are done with the creation of the sample project template with the addition of one controller named “JsonDemoController”.
 
Scenario 1: Send JSON Content welcome note based on user type
 
In this scenario, you will learn how to send a simple welcome note message in JSON format from the controller. Now, replace the existing code with the following code in the JsonDemoController.cs file.
    using System;  
    using System.Collections.Generic;  
    using System.Text;  
    using System.Web.Mvc;  
    using System.Web.Script.Serialization;  
    using JsonResultDemo.Models;  
      
    namespace JsonResultDemo.Controllers  
    {  
        public class JsonDemoController : Controller  
        {  
            #region ActionControllers  
      
            /// <summary>  
            /// Welcome Note Message  
            /// </summary>  
            /// <returns>In a Json Format</returns>  
            public JsonResult WelcomeNote()  
            {  
                bool isAdmin = false;  
                //TODO: Check the user if it is admin or normal user, (true-Admin, false- Normal user)  
                string output = isAdmin ? "Welcome to the Admin User" : "Welcome to the User";  
      
                return Json(output, JsonRequestBehavior.AllowGet);  
            }  
         }  
    }

Then, build the application (F6) and then hit the F5 to run an application and then navigate to the following URL http://localhost:49568/JsonDemo/WelcomeNote (It might be a chance to get a different Port Id at your end).

Then the displayed screen looks like the following.

In this scenario, you now have an idea of how to send a simple string in JSON format.
 
Scenario 2: Get the list of users in JSON Format
In this scenario, you will send a list of users in JSON format.
 
Step 1: Add a class file “UserModel.cs” like the following.

Click on “Class” and then the displayed link is as the following.

Enter the name as “UserModel.cs” and then click on the Add button.
 
Step 2: Update the code in UserMode.cs with the following code.
    using System;  
    using System.Collections.Generic;  
    using System.Linq;  
    using System.Web;  
      
    namespace JsonResultDemo.Models  
    {  
        public class UserModel  
        {  
            public int UserId { get; set; }  
            public string UserName { get; set; }  
            public string Company { get; set; }  
        }  
    }

Step 3: Add one method named GetUsers in the JsonDemoController.cs file that will return the list of sample users.
            /// <summary>  
            /// Get the Users  
            /// </summary>  
            /// <returns></returns>  
            private List<UserModel> GetUsers()  
            {  
                var usersList = new List<UserModel>  
                {  
                    new UserModel  
                    {  
                        UserId = 1,  
                        UserName = "Ram",  
                        Company = "Mindfire Solutions"  
                    },  
                    new UserModel  
                    {  
                        UserId = 1,  
                        UserName = "chand",  
                        Company = "Mindfire Solutions"  
                    },  
                    new UserModel  
                    {  
                        UserId = 1,  
                        UserName = "Abc",  
                        Company = "Abc Solutions"  
                    }  
                };  
      
                return usersList;  
            }

Step 4: Create one Action Controller method named GetUsersData with the following code in the JsonDemoController.cs file.
    /// <summary>  
            /// Get tthe Users data in Json Format  
            /// </summary>  
            /// <returns></returns>  
            public JsonResult GetUsersData()  
            {  
                var users = GetUsers();  
                return Json(users, JsonRequestBehavior.AllowGet);  
            }

Step 5: Run the application with this URL http://localhost:49568/JsonDemo/GetUsersData then the output looks like the following.
 

Scenario 3: Create JSON data at the client side and send content to the controller
 
In this scenario, you will create JSON data at the client side and then that data will be sent to the Controller action. The controller action request type is HttpPost.
 
Step 1: Create one Action controller method named Sample like the following in the JsonDemoController.cs file.

    /// <summary>  
    /// Sample View  
    /// </summary>  
    /// <returns></returns>  
    public ActionResult Sample()  
    {  
        return View();  
    }

Step 2: Create a View file named “Sample.cshtml” by right-clicking on View() in the Sample action controller method then click on “Add View” in the Sample action like the following.

By clicking on Add View it opens a popup and deselects the "Use a layout page" option. It then should look as in the following.

Now, click on the OK button then the sample.cshtml file will be created.
 
Step 3: Replace it with the following cshtml code in the sample.cshtml file.

    @{  
        Layout = null;  
    }  
      
    <!DOCTYPE html>  
      
    <html>  
        <head>  
            <meta name="viewport" content="width=device-width" />  
            <title>Create Sample JSON Data and send it to controller</title>  
        </head>  
        <body>  
            <div>  
                <label>Create Sample User JSON Data and send it to controller</label><br/><br />  
                <input type="button" id="btnUpdateUserDetail" value="Update User Detail" onclick="UpdateUserDetail();"/>  
            </div>  
        </body>  
    </html>  
    <script src="~/Scripts/jquery-1.10.2.min.js"></script>  
    <script lang="en" type="text/javascript">  
        function UpdateUserDetail() {  
            var usersJson = GetSampleUsersList();  
            var getReportColumnsParams = {  
                "usersJson": usersJson  
            };  
            $.ajax({  
                type: "POST",  
                traditional: true,  
                async: false,  
                cache: false,  
                url: '/JsonDemo/UpdateUsersDetail',  
                context: document.body,  
                data: getReportColumnsParams,  
                success: function (result) {  
                    alert(result);  
                },  
                error: function (xhr) {  
                    //debugger;  
                    console.log(xhr.responseText);  
                    alert("Error has occurred..");  
                }  
            });  
        }  
        function GetSampleUsersList() {  
            var userDetails = {};  
            var usersList = [];  
            for (var i = 1; i <= 3; i++) {  
                userDetails["UserId"] = i;  
                userDetails["UserName"] = "User- " + i;  
                userDetails["Company"] = "Company- " + i;  
                usersList.push(userDetails);  
            }  
            return JSON.stringify(usersList);  
        }  
    </script>

The following is a brief description of the Sample.cshtml file:
    The HTML body contains a label, about, to describe the functionality and one input button with an onclick of the UpdateUserDetail() function.

    The JavaScript part contains the jQuery reference and it contains two functions.

    GetSampleUsersList() will return the sample users in a stringified JSON format.

    UpdateUserDetail() sends the ajax request of post type for JsonDemoController with UpdateUserDetail action.

Step 4: A Create Action method named UpdateUsersDetail in the JsonDemoController as in the following and put a breakpoint in this method on the first line of code to help to trace the details.
    /// <summary>  
    /// Update the user details  
    /// </summary>  
    /// <param name="usersJson">users list in JSON Format</param>  
    /// <returns></returns>  
    [HttpPost]  
    public JsonResult UpdateUsersDetail(string usersJson)  
    {  
        var js = new JavaScriptSerializer();  
        UserModel[] user = js.Deserialize<UserModel[]>(usersJson);  
      
        //TODO: user now contains the details, you can do required operations  
        return Json("User Details are updated");  
    }

Step 5: Build and run the application (hit F5) with the URL (http://localhost:49568/JsonDemo/Sample) then the resultant screen looks like the following.

Step 6: Now, click on the “Update User Detail” button as it appears in the aforesaid screenshot. Then the resultant screen looks like the following.

Step 7: Just review the preceding image, you can identify that you are able to send the JSON data to the controller action from the client side and as well as you have deserialized the JSON data and assigned that data to the UserModel entity.
 
Scenario 4: How to handle a huge amount of JSON Data
 
In this scenario, you will get an idea of how to send a huge amount of JSON Data. Actually, in certain scenarios, you must send a huge amount of data from a controller to a view. In that case, the following example will be helpful to you.
 
Step 1: Create one method named GetUsersHugeData() as in the following. It just helps to generate sample user data.  
            /// <summary>  
            /// Get the huge list of users  
            /// </summary>  
            /// <returns></returns>  
            private List<UserModel> GetUsersHugeData()  
            {  
                var usersList = new List<UserModel>();  
                UserModel user;  
                for (int i = 1; i < 51000; i++)  
                {  
                    user = new UserModel  
                    {  
                        UserId = i,  
                        UserName = "User-"+i,  
                        Company = "Company-"+i  
                    };  
                    usersList.Add(user);  
                }  
      
                return usersList;  
            }

Step 2: Create an Action method named GetUsersHugeList() like the following in the JsonDemoController.cs file.
    /// <summary>  
    /// Get the huge list of Users  
    /// </summary>  
    /// <returns></returns>  
    public JsonResult GetUsersHugeList()  
    {  
        var users = GetUsersHugeData();  
        return Json(users, JsonRequestBehavior.AllowGet);  
    }

Step 3: Now, build and run (hit F5) the application with the URL (http://localhost:49568/JsonDemo/GetUsersHugeList) then the error screen appears like the following.

Step 4: To fix the preceding error add the following code in the JsonDemoController file. This methods helps to update the MaxJsonLength property value to Int32.MaxValue.
     /// <summary>  
    /// Override the JSON Result with Max integer JSON lenght  
    /// </summary>  
    /// <param name="data">Data</param>  
    /// <param name="contentType">Content Type</param>  
    /// <param name="contentEncoding">Content Encoding</param>  
    /// <param name="behavior">Behavior</param>  
    /// <returns>As JsonResult</returns>  
    protected override JsonResult Json(object data, string contentType,  
        Encoding contentEncoding, JsonRequestBehavior behavior)  
    {  
        return new JsonResult()  
        {  
            Data = data,  
            ContentType = contentType,  
            ContentEncoding = contentEncoding,  
            JsonRequestBehavior = behavior,  
            MaxJsonLength = Int32.MaxValue  
        };  
    }

In the same way, you can increase the RecursionLimit property value. Also if you require JsonData with a depth (nested levels) greater than 100.
 
Step 5: Now, build and run (hit F5) the application with the URL (http://localhost:49568/JsonDemo/GetUsersHugeList) and then the huge data result appears instead of an error.

I have provided the formatted complete code for the JsonDemoController.cs file for what you have done until now in the aforesaid scenarios.
    using System;  
    using System.Collections.Generic;  
    using System.Text;  
    using System.Web.Mvc;  
    using System.Web.Script.Serialization;  
    using JsonResultDemo.Models;  
      
    namespace JsonResultDemo.Controllers  
    {  
        public class JsonDemoController : Controller  
        {  
            #region ActionControllers  
      
            /// <summary>  
            /// Welcome Note Message  
            /// </summary>  
            /// <returns>In a JSON Format</returns>  
            public JsonResult WelcomeNote()  
            {  
                bool isAdmin = false;  
                //TODO: Check the user if it is admin or normal user, (true-Admin, false- Normal user)  
                string output = isAdmin ? "Welcome to the Admin User" : "Welcome to the User";  
      
                return Json(output, JsonRequestBehavior.AllowGet);  
            }  
      
            /// <summary>  
            /// Get tthe Users data in JSON Format  
            /// </summary>  
            /// <returns></returns>  
            public JsonResult GetUsersData()  
            {  
                var users = GetUsers();  
                return Json(users, JsonRequestBehavior.AllowGet);  
            }  
      
            /// <summary>  
            /// Sample View  
            /// </summary>  
            /// <returns></returns>  
            public ActionResult Sample()  
            {  
                return View();  
            }  
      
            /// <summary>  
            /// Update the user details  
            /// </summary>  
            /// <param name="usersJson">users list in JSON Format</param>  
            /// <returns></returns>  
            [HttpPost]  
            public JsonResult UpdateUsersDetail(string usersJson)  
            {  
                var js = new JavaScriptSerializer();  
                UserModel[] user = js.Deserialize<UserModel[]>(usersJson);  
      
                //TODO: user now contains the details, you can do required operations  
                return Json("User Details are updated");  
            }  
              
            /// <summary>  
            /// Get the huge list of Users  
            /// </summary>  
            /// <returns></returns>  
            public JsonResult GetUsersHugeList()  
            {  
                var users = GetUsersHugeData();  
                return Json(users, JsonRequestBehavior.AllowGet);  
            }  
     
            #endregion  
     
     
            #region Methods  
      
            /// <summary>  
            /// Get the Users  
            /// </summary>  
            /// <returns></returns>  
            private List<UserModel> GetUsers()  
            {  
                var usersList = new List<UserModel>  
                {  
                    new UserModel  
                    {  
                        UserId = 1,  
                        UserName = "Ram",  
                        Company = "Mindfire Solutions"  
                    },  
                    new UserModel  
                    {  
                        UserId = 1,  
                        UserName = "chand",  
                        Company = "Mindfire Solutions"  
                    },  
                    new UserModel  
                    {  
                        UserId = 1,  
                        UserName = "Abc",  
                        Company = "Abc Solutions"  
                    }  
                };  
      
                return usersList;  
            }  
      
            /// <summary>  
            /// Get the huge list of users  
            /// </summary>  
            /// <returns></returns>  
            private List<UserModel> GetUsersHugeData()  
            {  
                var usersList = new List<UserModel>();  
                UserModel user;  
                for (int i = 1; i < 51000; i++)  
                {  
                    user = new UserModel  
                    {  
                        UserId = i,  
                        UserName = "User-"+i,  
                        Company = "Company-"+i  
                    };  
                    usersList.Add(user);  
                }  
      
                return usersList;  
            }  
      
            /// <summary>  
            /// Override the Json Result with Max integer JSON lenght  
            /// </summary>  
            /// <param name="data">Data</param>  
            /// <param name="contentType">Content Type</param>  
            /// <param name="contentEncoding">Content Encoding</param>  
            /// <param name="behavior">Behavior</param>  
            /// <returns>As JsonResult</returns>  
            protected override JsonResult Json(object data, string contentType,  
                Encoding contentEncoding, JsonRequestBehavior behavior)  
            {  
                return new JsonResult()  
                {  
                    Data = data,  
                    ContentType = contentType,  
                    ContentEncoding = contentEncoding,  
                    JsonRequestBehavior = behavior,  
                    MaxJsonLength = Int32.MaxValue  
                };  
            }  
     
            #endregion  
        }  
    }

You now have an idea of how to use a JsonResult type in MVC application with various scenarios. Now, it's time to test the controller action methods using the JsonDemoController.Test project.

Unit Testing the JsonResult in MVC
The main feature of MVC applications is it supports the Test Data Driven (TDD) approach. Since the Controller file is just a kind of class file, it's easy to implement the Test methods in the Test Project. Now you will learn how to test the JsonResult methods in the test project.
 
Step 1: Add a class file named “JsonDemoControllerTest.cs” to the JsonResultDemo.Tests projects like the following.

Click on “Class” to open a popup like the following and then update the name as “JsonDemoControllerTest.cs”.

Step 2: After clicking on the “Ok” button then the screen result looks like the following.

Step 3: Now, replace the existing code in the file JsonDeomControllerTest.cs with the following code.
    using System;  
    using System.Web.Mvc;  
    using Microsoft.VisualStudio.TestTools.UnitTesting;  
    using JsonResultDemo.Controllers;  
      
    namespace JsonResultDemo.Tests.Controllers  
    {  
        [TestClass]  
        public class JsonDemoControllerTest  
        {  
            [TestMethod]  
            public void WelcomeNote()  
            {  
                JsonDemoController controller = new JsonDemoController();  
      
                JsonResult result = controller.WelcomeNote();  
                string msg = Convert.ToString(result.Data);  
                // Assert  
                Assert.AreEqual("Welcome to the User", msg);  
            }  
        }  
    }

Brief Note about TestMethod of WelcomeNote()
    Create an object for JsonDemoController.

    Save the result of JsonDemoController controller method “WelcomeNote” method result in the “result” parameter of the type JsonResult.

    The string “msg” is assigned with the value from the JSON Result (result.Data).

    In this step, you are checking the expected output with the actual output using the Assert method. In a similar way, the Assert Method provides other options like AreNotEqual, AreSame, IsNotNull and so on.

Step 4: Right-click on the WelcomeNote method and click on “Run Unit Tests” then the screen result looks like the following.

Step 5: You can also do the “Run Tests” by the clicking of (Ctrl +R, T). Then you can view the results in Test Explorer like the following.

In a similar way, you can create more test methods and it will be helpful to check the functionality in various cases since it provides correct results or not. I hope this article gives you an idea of JsonResult, JsonResult Properties, the usage of JsonResult with various scenarios and how can you test the JsonResult using the Test Project.

This article introduces how to display bootstrap alerts dynamically from an ASP.NET Core 3.1 MVC Application. Bootstrap provides us with an easy way to create predefined alerts. Bootstrap alerts are available for any length of text, as well as an optional close button. An example of a bootstrap alert is given below.

    <div class="alert alert-success alert-dismissible">    
       <a href="#" class="close" data-dismiss="alert" aria-label="close">×</a>    
       <strong>Success!</strong> This alert box could indicate a successful or positive action.    
     </div>     

Let's follow the below steps to show the alerts dynamically from a simple ASP.NET Core 3.1 MVC Application.
 
Step 1
Create an ASP.NET Core 3.1 MVC Web App.

Step 2
Add a new folder and add an Enum into that folder and give a suitable name like this.

Step 3
Now create a common service like this.

The code snippet for the CommonServices.cs class is given below. A new static method ‘ShowAlert’ is added here which takes two parameters and returns html as string.
    public class CommonServices {  
        public static string ShowAlert(Alerts obj, string message) {  
            string alertDiv = null;  
            switch (obj) {  
                case Alerts.Success:  
                    alertDiv = "<div class='alert alert-success alert-dismissable' id='alert'><button type='button' class='close' data-dismiss='alert'>×</button><strong> Success!</ strong > " + message + "</a>.</div>";  
                    break;  
                case Alerts.Danger:  
                    alertDiv = "<div class='alert alert-danger alert-dismissible' id='alert'><button type='button' class='close' data-dismiss='alert'>×</button><strong> Error!</ strong > " + message + "</a>.</div>";  
                    break;  
                case Alerts.Info:  
                    alertDiv = "<div class='alert alert-info alert-dismissable' id='alert'><button type='button' class='close' data-dismiss='alert'>×</button><strong> Info!</ strong > " + message + "</a>.</div>";  
                    break;  
                case Alerts.Warning:  
                    alertDiv = "<div class='alert alert-warning alert-dismissable' id='alert'><button type='button' class='close' data-dismiss='alert'>×</button><strong> Warning!</strong> " + message + "</a>.</div>";  
                    break;  
            }  
            return alertDiv;  
        }  
    }   

Now let’s call this method from a controller which is saving records in the database. The following is the code snippet for the controller.
    // POST: EmployeeController/Create    
    [HttpPost]  
    [ValidateAntiForgeryToken]  
    public ActionResult Create([FromForm] EmployeeViewModel collection) {  
        try {  
            int result = 0;  
            if (ModelState.IsValid) {  
                Employee objEmp = new Employee();  
                objEmp.EmpName = collection.EmpName;  
                objEmp.Address = collection.Address;  
                objEmp.Email = collection.Email;  
                objEmp.Phone = collection.Phone;  
                objEmp.BankAccountNo = collection.BankAccountNo;  
                objEmp.CreatedOn = DateTime.Now;  
                objEmp.CreatedBy = "SYSTEM";  
                objEmp.ModifiedOn = null;  
                objEmp.ModifiedBy = null;  
                result = _empRepo.Add(objEmp).Result;  
                //return RedirectToAction("Index");    
                if (result > 0) {  
                    ViewBag.Alert = CommonServices.ShowAlert(Alerts.Success, "Employee added");  
                } else ViewBag.Alert = CommonServices.ShowAlert(Alerts.Danger, "Unknown error");  
            }  
            return PartialView("_Create");  
        } catch {  
            return View();  
        }  
    }   

Code Explanation
 In post type method we pass EmployeeViewModel class as a parameter as a model name that gets all data from the user.
    _empRepo.Add() is a custom method used to save the Employee records. ( Repository Pattern is used to save a record here. You can download complete source code from the GitHub link given below ).

Step 4
Now add the below line in the view like this. It helps to render the HTML from the ViewBag string returned from the static method.
    @Html.Raw(@ViewBag.Alert) 

The following is the complete code snippet for the view.
    @model CodeSample.Models.EmployeeViewModel  
    @{  
        ViewData["Title"] = "Add Employee";  
        Layout = "~/Views/Shared/_Layout.cshtml";  
    }  
      
    <h4>Add Employee</h4>  
    <hr />  
    <div class="row">     
        <div class="col-md-4">  
            <form asp-action="Create" asp-controller="Employee" method="post">  
                <div asp-validation-summary="ModelOnly" class="text-danger"></div>  
                <div class="form-group">  
                    <label asp-for="EmpName" class="control-label">Enter employee name</label>  
                    <input asp-for="EmpName" class="form-control" />  
                    <span asp-validation-for="EmpName" class="text-danger"></span>  
                </div>  
                <div class="form-group">  
                    <label asp-for="Email" class="control-label">Enter email</label>  
                    <input asp-for="Email" class="form-control" />  
                    <span asp-validation-for="Email" class="text-danger"></span>  
                </div>  
                <div class="form-group">  
                    <label asp-for="Phone" class="control-label">Enter Phone No.</label>  
                    <input asp-for="Phone" class="form-control" />  
                    <span asp-validation-for="Phone" class="text-danger"></span>  
                </div>  
                <div class="form-group">  
                    <label asp-for="Address" class="control-label">Enter Address</label>  
                    <textarea asp-for="Address" class="form-control"></textarea>  
                    <span asp-validation-for="Address" class="text-danger"></span>  
                </div>  
                <div class="form-group">  
                    <label asp-for="BankAccountNo" class="control-label">Enter Bank Account No.</label>  
                    <input asp-for="BankAccountNo" class="form-control" />  
                    <span asp-validation-for="BankAccountNo" class="text-danger"></span>  
                </div>  
                <div class="form-group">  
                    <input type="submit" id="SaveEmp" value="Create" class="btn btn-primary" />  
                </div>  
            </form>  
        </div>  
     </div>  
    <div class="row">  
        <div class="col-md-12">  
            <div class="form-group">  
                @Html.Raw(@ViewBag.Alert)  
            </div>  
        </div>  
    </div>  
      
     <div><a asp-action="Index">Back to List</a></div>  
      
     @section Scripts {  
      
            @{await Html.RenderPartialAsync("_ValidationScriptsPartial");}  
     }  

Now if something goes wrong and the application is unable to insert the record in the database, it will show an error alert like this.

Else it will show a success alert like this.

Here we saw how to display a bootstrap alert dynamically from ASP.NET Core 3.1 MVC Application. Hope you like this article and get some information from it.
 

Today I will share the way to install Bootstrap in ASP.NET MVC5 using Visual Studio 2019. Setup Bootstrap 3.3.1 to ASP.NET MVC 5
 
Right-click Project -> Manager NuGet Packages -> Click icon setting configuration, add package source.
 
https://api.nuget.org/v3/index.json

Continue by adding a package source (following image)

You search keyword “bootstrap” and then install

You can see bootstrap in project after a successful installation.

Okay, installation is successful!
You can use bootstrap in Layout file of Views/Shared/_LayoutHome.cshtml directory. (Note you add css,javascript to file)

    <link rel="stylesheet" href="~/Content/bootstrap.min.css" />  
    <script src="~/Scripts/jquery-3.3.1.min.js"></script>  
    <script src="~/Scripts/bootstrap.min.js"></script>  

Example - Views/Shared/_LayoutHome.cshtml

    <!DOCTYPE html>  
    <html>  
    <head>  
        <meta name="viewport" content="width=device-width" />  
        <title>@ViewBag.Title</title>  
        <link rel="stylesheet" href="~/Content/bootstrap.min.css" />  
        <script src="~/Scripts/jquery-3.3.1.min.js"></script>  
        <script src="~/Scripts/bootstrap.min.js"></script>  
    </head>  
    <body>  
        <div>  
            @RenderBody()  
        </div>  
    </body>  
    </html>  

Views/Home/Index.cshtml

    <div class="container">  
        <div class="row">  
            <div class="col-md-12">  
                <h2>@ViewBag.title</h2>  
                <a href="https://hostforlifeasp.net" class="btn btn-success">https://hostforlifeasp.net/</a>  
            </div>  
        </div>  
    </div>  

Ok, we successfully installed bootstrap in ASP.NET MVC 5

In this article I am going to cover some really interesting material that is very useful today in web application development. You will learn how to make jQuery Ajax GET and POST calls to controller methods.

When we use jQuery Ajax to access a server (controller's method) without reloading the web page we have two choices for how to pass the information for the request to the server (controller's method). These two options are to use either GET or POST.
 
Note: Before beginning with the code, ensure you are using the jQuery library before the GET or POST script.
 
GET
GET is used to request data from a specified resource. With all the GET request we pass the URL which is compulsory, however it can take the following overloads.
    .get( url [, data ] [, success(data, textStatus, jqXHR) ] [, dataType ] ).done/.fail  

Now, let's try to use GET in MVC application.
 
GET call to Controller's Method that will return string data
 
Let's imagine we have the following method in the controller:
    public string TellMeDate()  
    {  
        return DateTime.Today.ToString();  
    }  

This method will return string data (date-time) when we call it, let's make an async call using jQuery Ajax.
    <p id="rData">  
    </p>   
    <script type="text/jscript">  
        var url = "/Home/TellMeDate";  
        $.get(url, null, function (data) {  
            $("#rData").html(data);  
        });  
    </script>  

When the page gets loaded, jQuery Ajax will generate an Ajax GET request/call. The first parameter is the URL and the second is data (this is an optional, even we can avoid typing "null") and the third is the success function when the response is received. The success function takes one parameter "data" that holds the string content and we attached this content to a DOM element.
 
If you want to generate an Ajax GET request when the user clicks a button then can use the following instead:
    <script type="text/jscript">  
        $('#ButtonID').click(function () {  
            var url = "/Home/TellMeDate";  
            $.get(url, null, function (data) {  
                $("#rData").html(data);  
            });  
        })  
    </script>  

If you run the application, you will see the following output:

GET call with parameter to Controller's Method that will return string data
 
Let's imagine we have the following method in the controller:
    public string WelcomeMsg(string input)  
    {  
        if (!String.IsNullOrEmpty(input))  
            return "Please welcome " + input + ".";  
        else  
            return "Please enter your name.";  
    }   

This method will accept a parameter and will return string data (a welcome message or instruction message) when we call it. Now, let's make an async call to this method using jQuery Ajax.
    <p>  
        Enter you name @Html.TextBox("Name")  
        <input type="submit" id="SubmitName" value="Submit"/>  
    </p>   
    <script type="text/jscript">  
        $('#SubmitName').click(function () {  
            var url = "/Home/WelcomeMsg";  
            var name = $('#Name').val();  
            $.get(url, { input: name }, function (data) {  
                $("#rData").html(data);  
            });  
        })  
    </script>   

As you can see, when we click the button after typing a name in the TextBox, jQuery Ajax will generate an Ajax GET request/call. Notice that the second parameter to the "get" function now contains a key { input: name } (parameter). This example supplies one parameter, but can be extended to provide multiple parameters.

GET call with parameter to Controller's Method that will return JSON data
 
The Controller's method we used above returns simple strings. Now, to deal with complex data we need JSON. The following method will return a JsonResult having the customer's ContactName and Address from NorthwindEntities. I am using the Northwind database and EF Database First approach in this sample.
    public JsonResult CustomerList(string Id)  
    {  
        NorthwindEntities db = new NorthwindEntities();  
        var result = from r in db.Customers  
                        where r.Country == Id  
                        select new { r.ContactName, r.Address };  
        return Json(result, JsonRequestBehavior.AllowGet);  
    }   

The above method will accept Id as a parameter and return a "JsonResult". This action method can be called using the following jQuery Ajax GET call:
    <p id="rData">  
    </p>   
    <p>  
        Enter country name @Html.TextBox("Country")  
        <input type="submit" id="GetCustomers" value="Submit"/>  
    </p>   
    <script type="text/jscript">  
        $('#GetCustomers').click(function () {  
            $.getJSON('/Home/CustomerList/' + $('#Country').val(), function (data) {   
                var items = '<table><tr><th>Name</th><th>Address</th></tr>';  
                $.each(data, function (i, country) {  
                    items += "<tr><td>" + country.ContactName + "</td><td>" + country.Address + "</td></tr>";  
                });  
                items += "</table>";   
                $('#rData').html(items);  
            });  
        })  
    </script>   

As you can see, when we click the button after typing a country name in the TextBox, jQuery Ajax will generate an Ajax GET request/call. Notice that the "getJSON" function now contains an URL in the format "/Controller/ActionMethod/Key", here the key (parameter) is the supplied country name.

Using Firebug we can sniff the response. We have used a TextBox where we typed the country name and clicked on a button to get the list of customers.
 
Alternatively, we can populate the list of countries in the dropdownlist box and then when the user selects the country name from the dropdownlist, we can display the list of customers.   

Here is the controller that will populate the country list in the dropdownlist box:
    public ActionResult About()  
    {  
        var result = from r in db.Customers  
                        select r.Country;  
        ViewBag.Country = result;   
        return View();  
    }   

Now, once we have a list of countries in the dropdownlist box, we can implement an Ajax GET request/call. Here it is with a complete view page.
    @Html.DropDownListFor(model => model.Country, new SelectList(ViewBag.Country), "Select Country")   
    <p id="rData">  
    </p>   
    @section Scripts {  
        <script type="text/jscript">  
            $('#Country').click(function () {  
                $.getJSON('/Home/CustomerList/' + $('#Country').val(), function (data) {   
                    var items = '<table><tr><th>Name</th><th>Address</th></tr>';  
                    $.each(data, function (i, country) {  
                        items += "<tr><td>" + country.ContactName + "</td><td>" + country.Address + "</td></tr>";  
                    });  
                    items += "</table>";   
                    $('#rData').html(items);  
                });  
            })  
        </script>  
    }   

Everything remains the same as in the TextBox version above.
 
POST
POST is used to submit data to be processed to a specified resource. With all the POST requests we pass the URL which is compulsory and the data, however it can take the following overloads.  
    .post( url [, data ] [, success(data, textStatus, jqXHR) ] [, dataType ] )   

Now, let's try to use POST in a MVC application.
 
POST call to Controller's Method to save TextBox data (not form)
 
There are various ways to POST form data to a method but in the example given below I'm not going to use any form. I will just use two textboxes and a submit button, when the user clicks the button I want to save the data using a jQuery Ajax POST call. So, here is the method accepting the two parameters for name and address:
    [HttpPost]  
    public string SubmitSubscription(string Name, string Address)  
    {  
        if (!String.IsNullOrEmpty(Name) && !String.IsNullOrEmpty(Address))  
            //TODO: Save the data in database  
            return "Thank you " + Name + ". Record Saved.";  
        else  
            return "Please complete the form.";             
    }   

We can implement method above to save the data in the database, it will also return the response back to the client. Here is the jQuery Ajax POST function:
    <h2>Subscription</h2>   
    <p>  
        Enter your name  
        <br />  
        @Html.TextBox("Name")  
    </p>  
    <p>  
        Enter your address  
        <br />  
        @Html.TextBox("Address")  
    </p>   
    <input type="button" value="Save" id="Save" />  
    <span id="msg" style="color:red;"/>   
    <script type="text/javascript">  
        $('#Save').click(function () {  
            var url = "/Home/SubmitSubscription";  
            var name = $("#Name").val();  
            var address = $("#Address").val();  
            $.post(url, { Name: name, Address: address }, function (data) {  
                $("#msg").html(data);  
            });  
        })  
    </script>   

POST call to Controller's Method to save form data
In case above we don't have a form, so I have used two individual properties/parameters (name and address) with a jQuery Ajax POST call and also on the method side, but this approach will be painful since the number of properties increase. In this case we can use the model approach that will allow us to work with intelisense. So, let's go and create the "Subscription" model class with two properties.
    public class Subscription  
    {  
        public string Name { get; set; }  
        public string Address { get; set; }  
    }  

Now that we have the model we can create our controller method:
    [HttpPost]  
    public string SubmitSubscription(Subscription subs)  
    {  
        if (!String.IsNullOrEmpty(subs.Name) && !String.IsNullOrEmpty(subs.Address))  
            //TODO: Save the data in database  
            return "Thank you " + subs.Name + ". Record Saved.";  
        else  
            return "Please complete the form.";             
    }  

Still the same, just using a model instead of individual properties.
    <h2>Subscription</h2>   
    <form id="subscriptionForm" action="/Home/SubmitSubscription" method="post">  
    <p>  
        Enter your name  
        <br />  
        @Html.TextBox("Name")  
    </p>  
    <p>  
        Enter your address  
        <br />  
        @Html.TextBox("Address")  
    </p>   
    <input type="button" value="Save" id="Save" />  
    <span id="msg" style="color:red;"/>  
    </form>   
    @section Scripts{  
        <script type="text/javascript">  
            $('#Save').click(function () {   
                var form = $("#subscriptionForm");  
                var url = form.attr("action");  
                var formData = form.serialize();  
                $.post(url, formData, function (data) {  
                    $("#msg").html(data);  
                });  
            })  
        </script>  
    }  

Noting new, everything is the same, just a few changes that allow us to work with a form.

In many forum posts, developers and students have asked one common question, that is, how to use Web API REST Service in ASP.NET MVC application and how to make a call between them to exchange the information. So, considering this demand, I have decided to write this article to demonstrate how to consume ASP.NET Web API REST Service in ASP.NET MVC application with the help of HttpClient.

 
Prerequisites
If you don't know what is Web API REST service and how to create, publish, host ASP.NET Web API REST Service, then please refer to my video as well as articles, using the following links. Also, follow the same sequence if you want to learn web API REST service from creating to hosting to consuming in client application.
    Creating ASP.NET Web API REST Service
    Publishing ASP.NET Web API REST Service Using File System Method
    Hosting ASP.NET Web API REST Service on IIS 10

In this article, we will use the same hosted Web API REST service to consume in our created ASP.NET MVC web application. Now, let's start consuming Web API REST service in ASP.NET MVC application step by step.

Step 1 - Create MVC Application.
    "Start", followed by "All Programs" and select "Microsoft Visual Studio 2015".

    Click "File", followed by "New" and click "Project". Select "ASP.NET Web Application Template", provide the Project a name as you wish and click OK.

    After clicking, the following Window will appear. Choose empty project template and check on MVC option.

The preceding step creates the simple empty ASP.NET MVC application without Model, View, and Controller, The Solution Explorer of created web application will look like the following.

Step 2 - Install HttpClient library from NuGet
We are going to use HttpClient to consume the Web API REST Service, so we need to install this library from NuGet Package Manager .
 
What is HttpClient?
HttpClient is base class which is responsible to send HTTP request and receive HTTP response resources i.e from REST services.
To install HttpClient, right click on Solution Explorer of created application and search for HttpClient, as shown in the following image.

Now, click on "Install" button after choosing the appropriate version. It will get installed after taking few seconds, depending on your internet speed.
 
Step 3 - Install WebAPI.Client library from NuGet
This package is used for formatting and content negotiation which provides support for System.Net.Http. To install, right click on Solution Explorer of created application and search for WebAPI.Client, as shown in following image.

Now, click on "Install" button after choosing the appropriate version. It will get installed after taking few seconds depending on your internet speed. We have installed necessary NuGet packages to consume Web API REST services in web application. I hope you have followed the same steps.
 
Step 4 - Create Model Class
Now, let us create the Model class named Employee.cs  or as you wish, by right clicking on Models folder with same number of entities which are exposing by our hosted Web API REST service to exchange the data. The code snippet of created Employee.cs class will look like this.
 
Employee.cs
    public class Employee  
    {  
        public int Id { get; set; }  
        public string Name { get; set; }  
                 
        public string City { get; set; }  
      
    }   

Step 5 - Add Controller Class
Now, let us add ASP.NET MVC controller, as shown in the screenshot given below.

After clicking Add button, it will show in the Window. Specify the Controller name as Home with suffix Controller. Now, let's modify the default code of Home controller .
 
Our hosted Web API REST Service includes these two methods, as given below.

    GetAllEmployees (GET )
    GetEmployeeById (POST ) which takes id as input parameter

We are going to call GetAllEmployees method which returns the all employee details ,The hosted web api REST service base URL is http://192.168.95.1:5555/ and to call GetAllEmployees from hosted web API REST service, The URL should be Base url+api+apicontroller name +web api method name as following,

http://192.168.95.1:5555/api/Employee/GetAllEmployees

In the preceding url

    http://localhost:56290 Is the base address of web API service, It can be different as per your server.
    api It is the used to differentiate between Web API controller and MVC controller request .
    Employee This is the Web API controller name.
    GetAllEmployees This is the Web API method which returns the all employee list.

After modifying the code of Homecontroller class, the code will look like the following.
 
Homecontroller.cs
    using ConsumingWebAapiRESTinMVC.Models;  
    using Newtonsoft.Json;  
    using System;  
    using System.Collections.Generic;  
    using System.Net.Http;  
    using System.Net.Http.Headers;  
    using System.Threading.Tasks;  
    using System.Web.Mvc;  
      
    namespace ConsumingWebAapiRESTinMVC.Controllers  
    {  
        public class HomeController : Controller  
        {  
            //Hosted web API REST Service base url  
            string Baseurl = "http://192.168.95.1:5555/";      
            public async Task<ActionResult> Index()  
            {  
                List<Employee> EmpInfo = new List<Employee>();  
                  
                using (var client = new HttpClient())  
                {  
                    //Passing service base url  
                    client.BaseAddress = new Uri(Baseurl);  
      
                    client.DefaultRequestHeaders.Clear();  
                    //Define request data format  
                    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));  
                      
                    //Sending request to find web api REST service resource GetAllEmployees using HttpClient  
                    HttpResponseMessage Res = await client.GetAsync("api/Employee/GetAllEmployees");  
      
                    //Checking the response is successful or not which is sent using HttpClient  
                    if (Res.IsSuccessStatusCode)  
                    {  
                        //Storing the response details recieved from web api   
                        var EmpResponse = Res.Content.ReadAsStringAsync().Result;  
      
                        //Deserializing the response recieved from web api and storing into the Employee list  
                        EmpInfo = JsonConvert.DeserializeObject<List<Employee>>(EmpResponse);  
      
                    }  
                    //returning the employee list to view  
                    return View(EmpInfo);  
                }  
            }  
        }  
    }

I hope, you have gone through the same steps and understood about the how to use and call Web API REST service resource using HttpClient .
 
Step 6 - Create strongly typed View
Now, right click on Views folder of the created application and create strongly typed View named by Index by choosing Employee class to display the employee list from hosted web API REST Service, as shown in the following image.

Now, click on "Add" button. It will create View named index after modifying the default code. The code snippet of the Index View looks like the following.

Index.cshtml
    @model IEnumerable<ConsumingWebAapiRESTinMVC.Models.Employee>  
      
    @{  
        ViewBag.Title = "www.compilemode.com";  
    }  
      
    <div class="form-horizontal">  
      
        <hr />  
        <div class="form-group">  
      
      
            <table class="table table-responsive" style="width:400px">  
                <tr>  
                    <th>  
                        @Html.DisplayNameFor(model => model.Name)  
                    </th>  
                    <th>  
                        @Html.DisplayNameFor(model => model.City)  
                    </th>  
                      
                </tr>  
      
                @foreach (var item in Model) {  
                    <tr>  
                        <td>  
                            @Html.DisplayFor(modelItem => item.Name)  
                        </td>  
                        <td>  
                            @Html.DisplayFor(modelItem => item.City)  
                        </td>  
                          
                    </tr>  
    }  
      
            </table>  
        </div>  
    </div>

The preceding View will display all employees list . Now, we have done all the coding.

Step 7 - Run the Application